Question: If $x \oplus y = 7x-y$ and $x \dagger y = xy+2x-y$, find $(-2 \dagger -1) \oplus -3$.
First, find $-2 \dagger -1$ $ -2 \dagger -1 = (-2)(-1)+(2)(-2)-(-1)$ $ \hphantom{-2 \dagger -1} = -1$ Now, find $-1 \oplus -3$ $ -1 \oplus -3 = (7)(-1)-(-3)$ $ \hphantom{-1 \oplus -3} = -4$.